Robotic transanal minimally invasive surgery (R-TAMIS): current evidence in the treatment of early rectal neoplasia.

INTRODUCTION: Robotic transanal minimally invasive surgery (R-TAMIS) was introduced in 2012 for the excision of benign rectal polyps and low grade rectal cancer. Ergonomic improvements over traditional laparoscopic TAMIS (L-TAMIS) include increased dexterity within a small operative field, with possibility of better surgical precision. We aim to collate the existing data surrounding the use of R-TAMIS to treat rectal neoplasms from cohort studies and larger case series, providing a foundation for future, large-scale, comparative studies. METHODS: Medline, EMBASE and Web of Science were searched as part of our review. Randomised controlled trials (RCTs), cohort studies or large case series (≥ 5 patients) investigating the use of R-TAMIS to resect rectal neoplasia (benign or malignant) were eligible for inclusion in our analysis. Quality assessment of included studies was performed via the Newcastle Ottawa Scale (NOS) risk of bias tool. Outcomes extracted included basic participant characteristics, operative details and histopathological/oncological outcomes. RESULTS: Eighteen studies on 317 participants were included in our analysis. The quality of studies was generally satisfactory. Overall complication rate from R-TAMIS was 9.7%. Clear margins (R0) were reported in 96.2% of patients. Local recurrence (benign or malignant) occurred in 2.2% of patients during the specified follow-up periods. CONCLUSION: Our review highlights the current evidence for R-TAMIS in the local excision of rectal lesions. While R-TAMIS appears to have complication, margin negativity and recurrence rates superior to those of published L-TAMIS series, comparative studies are needed.

Assessing circulating tumour DNA (ctDNA) as a prognostic biomarker in locally advanced rectal cancer: a systematic review and meta-analysis.

INTRODUCTION: Circulating tumour DNA (ctDNA) has emerged as a promising biomarker in various cancer types, including locally advanced rectal cancer (LARC), offering potential insights into disease progression, treatment response and recurrence. This review aims to comprehensively evaluate the utility of ctDNA as a prognostic biomarker in LARC. METHODS: PubMed, EMBASE and Web of Science were searched as part of our review. Studies investigating the utility of ctDNA in locally advanced rectal cancer (LARC) were assessed for eligibility. Quality assessment of included studies was performed using the Newcastle Ottawa Scale (NOS) risk of bias tool. Outcomes extracted included basic participant characteristics, ctDNA details and survival data. A meta-analysis was performed on eligible studies to determine pooled recurrence-free survival (RFS). RESULTS: Twenty-two studies involving 1676 participants were included in our analysis. Methodological quality categorised by the Newcastle Ottawa Scale was generally satisfactory across included studies. ctDNA detected at various time intervals was generally associated with poor outcomes across included studies. Meta-analysis demonstrated a pooled hazard ratio of 8.87 (95% CI 4.91-16.03) and 15.15 (95% CI 8.21-27.95), indicating an increased risk of recurrence with ctDNA positivity in the post-neoadjuvant and post-operative periods respectively. CONCLUSION: Our systematic review provides evidence supporting the prognostic utility of ctDNA in patients with LARC, particularly in identifying patients at higher risk of disease recurrence in the post-neoadjuvant and post-operative periods.

Assessing Circulating Tumour DNA (ctDNA) as a Biomarker for Anal Cancer Management: A Systematic Review.

This systematic review investigates the potential of circulating tumour DNA (ctDNA) as a predictive biomarker in the management and prognosis of squamous cell carcinoma of the anal canal (SCCA). PubMed, EMBASE, and Cochrane Central Registry of Controlled Trials were searched until 7 January 2024. Selection criteria included research articles exploring ctDNA in the context of anal cancer treatment response, recurrence risk assessment, and consideration of salvage surgery. A total of eight studies were therefore included in the final review, examining a total of 628 patients. These studies focused on three main themes: SCCA diagnosis and staging, treatment response, and patient outcomes. Significant heterogeneity was observed in terms of patient cohort, study methodology, and ctDNA biomarkers. Four studies provided information on the sensitivity of ctDNA biomarkers in SCCA, with a range of 82-100%. Seven studies noted a correlation between pre-treatment ctDNA levels and SCCA disease burden, suggesting that ctDNA could play a role as a biomarker for the staging of SCCA. Across all seven studies with paired pre- and post-treatment ctDNA samples, a trend was seen towards decreasing ctDNA levels post-treatment, with specific identification of a 'fast elimination' group who achieve undetectable ctDNA levels prior to the end of treatment and may be less likely to experience treatment failure. Residual ctDNA detection post-treatment was associated with poorer patient prognosis. This systematic review identifies the broad potential of ctDNA as a useful and decisive tool in the management of SCCA. Further analysis of ctDNA biomarkers that include larger patient cohorts is required in order to clearly evaluate their potential role in clinical decision-making processes.

Survival outcomes after synchronous para-aortic lymph node metastasis in colorectal cancer: A systematic review.

BACKGROUND: Synchronous para-aortic lymph node metastasis (PALNM) in colorectal cancer (CRC) is a relatively rare clinical entity. There is a lack of consensus on management of these patients, and the role of para-aortic lymph node dissection (PALND) remains controversial. This systematic review aims to describe the survival outcomes in colorectal cancer with synchronous PALNM when lymph node dissection is performed. METHODS: A systematic review of Pubmed, Embase and Web of Science databases for PALND in CRC was performed. Studies including patients with synchronous PALNM undergoing resection with curative intent, published from the year 2000 onwards, were included. RESULTS: Twelve retrospective studies were included. Four studies reported survival outcomes for rectal cancer, two for colon cancer and six as colorectal. Survival outcomes for 356 patients were included. Average 5-year overall survival (OS) was 22.4%, 33.9% and 37.7% in the rectal, colon and colorectal groups respectively. Three year OS in the groups was 53.6%, 46.2% and 65.7%. CONCLUSION: There remains a lack of quality data to confidently make recommendations regarding the management of synchronous PALNM in colon and rectal cancer cohorts. Retrospective data suggests a benefit in highly selective cohorts and therefore a case-by-case evaluation remains the standard of care.

A multicentre study assessing the role of routine colonoscopy after acute uncomplicated diverticulitis and the incidence of colorectal cancer diagnosis.

PURPOSE: The low rates of colonic malignancy detected on interval colonoscopy for patients diagnosed with diverticulitis have led recent studies to question the utility of the practice. The aim of this study was to assess the detection rate of colorectal cancer on colonoscopy for patients with a first episode of acute uncomplicated diverticulitis across three separate centres in Ireland and the UK. METHODS: A retrospective review was performed of patients with a first episode of acute, uncomplicated diverticulitis who underwent interval colonoscopy at three separate centres in the UK and Ireland between 2007 and 2019. The follow-up period was one year. RESULTS: A total of 5485 patients were admitted with acute diverticulitis between the three centres. All patients had CT verified diverticulitis. A 90.8% (n = 4982) underwent subsequent colonic evaluation with colonoscopy. Of these, a histologically proven diagnosis of colorectal carcinoma was made in 1.28% (n = 64). CONCLUSION: Routine colonoscopy following an episode of acute, uncomplicated diverticulitis may not be necessary in every patient. It may be appropriate to reserve this more invasive investigation for those with higher risk factors for malignancy.

Application of PREVENA (Surgical Incision Protection System) in reducing surgical site infections following reversal of ileostomy or colostomy: the PRIC study protocol.

AIM: There is a current lack of evidence in the literature to support the routine use of negative pressure wound therapy (NPWT) to reduce the risk of surgical site infections (SSI) in the setting of ileostomy or colostomy reversal. The aim of this study is to examine whether routine NPWT confers a lower rate of SSI than conventional dressings following reversal of ileostomy or colostomy. METHODS: The PRIC study is a randomized, controlled, open-label, multi-centre superiority trial to assess whether routine NPWT following wound closure confers a lower rate of SSI following reversal of ileostomy or colostomy when compared to conventional dressings. Participants will be consecutively identified and recruited. Eligible participants will be randomized in a 1:1 allocation ratio, to receive either the NPWT (PREVENA) dressings or conventional dressings which will be applied immediately upon completion of surgery. PREVENA dressings will remain applied for a duration of 7 days. Surgical wounds will then be examined on post-operative day seven as well as during follow-up appointments in OPD for any evidence of SSI. In the interim, public health nurses (PHN) will provide out-patient support services incorporating wound assessment and care as part of a routine basis. Study investigators will liaise with PHN to gather the relevant data in relation to the time to wound healing. Our primary endpoint is the incidence of SSI within 30 days of stoma reversal. Secondary endpoints include measuring time to wound healing, evaluating wound healing and aesthetics and assessing patient satisfaction. CONCLUSION: The PRIC study will assess whether routine NPWT following wound closure is superior to conventional dressings in the reduction of SSI following reversal of ileostomy or colostomy and ascertain whether routine NPWT should be considered the new standard of care.

Prostate radiotherapy and the risk of secondary rectal cancer-a meta-analysis.

PURPOSE: Radiotherapy is being used increasingly in the treatment of prostate cancer. However, ionising radiation may confer a small risk of a radiation-induced secondary malignancy. We aim to assess the risk of rectal cancer following pelvic radiotherapy for prostate cancer. METHODS: A search was conducted of the PubMed/MEDLINE, EMBASE and Web of Science databases identifying studies reporting on the risk of rectal cancer following prostatic radiotherapy. Studies must have included an appropriate control group of non-irradiated prostate cancer patients. A meta-analysis was performed to assess the risk of prostatic radiotherapy on subsequent rectal cancer diagnosis. RESULTS: In total, 4757 articles were screened with eight studies meeting the predetermined criteria. A total of 796,386 patients were included in this meta-analysis which showed an increased odds ratio (OR) for subsequent rectal cancer in prostate cancer patients treated with radiotherapy compared to those treated by non-radiotherapy means (OR 1.45, 1.07-1.97, p = 0.02). CONCLUSION: These findings confirm that prostate radiotherapy significantly increases the risk of subsequent rectal cancer. This risk has implications for treatment selection, surveillance and patient counselling. However, it is crucial that this information is presented in a rational and comprehensible manner that does not disproportionately frighten or deter patients from what might be their most suitable treatment modality.

Quality of life meta-analysis following coloanal anastomosis versus abdominoperineal resection for low rectal cancer.

AIM: In low rectal cancers without sphincter involvement a permanent stoma can be avoided without compromising oncological safety. Functional outcomes following coloanal anastomosis (CAA) compared to abdominoperineal excision (APR) may be significantly different. This study examines all available comparative quality of life (QoL) data for patients undergoing CAA versus APR for low rectal cancer. METHODS: Published studies with comparative data on QoL outcomes following CAA versus APR for low rectal cancer were extracted from electronic databases. The study was registered with PROSPERO and adhered to PRISMA (Preferred Reporting Items in Systematic Reviews and Meta-analyses) guidelines. Data was combined using random-effects models. RESULTS: Seven comparative series examined QoL in 527 patients. There was no difference in the numbers receiving neoadjuvant radiotherapy in the APR and CAA groups (OR: 1.19, 95% CI: 0.78-1.81, p = 0.43). CAA was associated with higher mean scores for physical functioning(std mean diff -7.08, 95% CI: -11.92 to -2.25, p = 0.004) and body image (std. mean diff 11.11, 95% CI: 6.04-16.18, p < 0.0001). Male sexual problems were significantly increased in patients who had undergone APR compared to CAA (std. mean diff -16.20, 95% CI: -25.76 to -6.64, p = 0.0009). Patients who had an APR reported more fatigue, dyspnoea and appetite loss. Those who had a CAA reported higher scores for both constipation and diarrhoea. DISCUSSION: It is reasonable to offer a CAA to motivated patients where oncological outcomes will not be threatened. QoL outcomes appear to be superior when intestinal continuity is maintained, and permanent stoma avoided.

Optimal surgical management strategy for treatment of primary anorectal malignant melanoma-a systematic review and meta-analysis.

BACKGROUND: Primary mucosal anorectal malignant melanoma (AMM) is an invasive malignancy with poor survival. Management options have been variable, due to limited data and lack of randomised control trials available on the optimal surgical strategy. The aim of this review was to compare local excision versus radical resection. METHODS: A systematic search of articles in PubMed, Ovid, Scopus, and the Cochrane Library database was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The outcomes of interest were the impact that surgical strategy had on survival (primary) and recurrence rates (secondary) for the treatment of AMM, comparing sphincter sparing local excision (LE) versus extensive abdominoperineal resection (APR). RESULTS: Ten studies met the predefined criteria. Overall, there were 303 patients, with a median age of 58.2 years. Sixty-one percent (n = 187/303) had radical surgery (abdominoperineal resection) for the primary treatment of AMM. Overall, 5-year survival for the APR and LE was 23% and 32% respectively. Meta-analysis on the median OS noted no statistical difference between the two groups. However, local recurrence occurred in 20.82% and 47.04% in the APR and LE groups respectively. Meta-analysis observed a statistically significant reduction in recurrence when patients had an APR as primary treatment (OR 0.15, 95% CI = 0.08-0.28, p < 0.00001). CONCLUSION: Though local recurrence rates are more common with local excision of AMM, this does not confer an inferior OS when comparing LE versus APR. The decision to proceed with LE vs. APR should be made on a case-by-case basis.

Obesity and anastomotic leak rates in colorectal cancer: a meta-analysis.

PURPOSE: Anastomotic leak (AL) following colorectal cancer resection is associated with considerable morbidity and mortality with an impact on recurrence rates and survival. The impact of obesity on AL rates is debated. This meta-analysis aims to investigate the relationship between obesity and AL. METHODS: A search was conducted of the PubMed/MEDLINE, and Web of Science databases and included studies were split into Western and Asian groups based on population-specific body mass index (BMI) ranges for obesity. A meta-analysis was performed to assess the impact of obesity on AL rate following colorectal cancer resection. RESULTS: Two thousand three hundred and four articles were initially screened. Thirty-one studies totaling 32,953 patients were included. Patients with obesity had a statistically significant increase in AL rate in all Western and Asian study groups. However, this increase was only clinically significant in the rectal anastomotic subgroups-Western: 10.8% vs 8.4%, OR 1.57 (1.01-2.44) and Asian: 9.4% vs 7.4%, OR 1.58 (1.07-2.32). CONCLUSIONS: The findings of this analysis confirm that obesity is a significant risk factor for anastomotic leak, particularly in rectal anastomoses. This effect is thought to be primarily mediated via technical difficulties of surgery although metabolic and immunological factors may also play a role. Obesity in patients undergoing restorative CRC resection should be discussed and considered as part of the pre-operative counselling.

Combining 1,4-dihydroxy quininib with Bevacizumab/FOLFOX alters angiogenic and inflammatory secretions in ex vivo colorectal tumors.

BACKGROUND: Colorectal cancer (CRC) is the second most common cause of cancer-related mortality worldwide with one in every five patients diagnosed with metastatic CRC (mCRC). In mCRC cases, the 5-year survival rate remains at approximately 14%, reflecting the lack of effectiveness of currently available treatments such as the anti-VEGF targeting antibody Bevacizumab combined with the chemotherapy folinic acid, fluorouracil and oxaliplatin (FOLFOX). Approximately 60% of patients do not respond to this combined treatment. Furthermore, Bevacizumab inhibits dendritic cell (DC) maturation in poor responders, a key process for tumor eradication. METHOD: Following drug treatment, secreted expression levels of angiogenic and inflammatory markers in tumor conditioned media generated from human ex vivo colorectal tumors were measured by ELISA. Dendritic cell phenotypic and maturation markers were assessed by flow cytometry. RESULTS: Our novel compound, 1,4-dihydroxy quininib, acts in an alternative pathway compared to the approved therapy Bevacizumab. 1,4-dihydroxy quininib alone, and in combination with Bevacizumab or FOLFOX significantly reduced TIE-2 expression which is involved in the promotion of tumor vascularization. Combination treatment with 1,4-dihydroxy quininib significantly increased the expression level of DC phenotypic and maturation markers. CONCLUSION: Our results indicate the anti-angiogenic small molecule 1,4-dihydroxy quininib could be an alternative novel treatment in combination therapy for CRC patients.

The tumour microenvironment of the upper and lower gastrointestinal tract differentially influences dendritic cell maturation.

BACKGROUND: Only 10-30% of oesophageal and rectal adenocarcinoma patients treated with neoadjuvant chemoradiotherapy have a complete pathological response. Inflammatory and angiogenic mediators in the tumour microenvironment (TME) may enable evasion of anti-tumour immune responses. METHODS: The TME influence on infiltrating dendritic cells (DCs) was modelled by treating immature monocyte-derived DCs with Tumour Conditioned Media (TCM) from distinct gastrointestinal sites, prior to LPS-induced maturation. RESULTS: Cell line conditioned media from gastrointestinal cell lines inhibited LPS-induced DC markers and TNF-α secretion. TCM generated from human tumour biopsies from oesophageal, rectal and colonic adenocarcinoma induced different effects on LPS-induced DC markers - CD54, CD80, HLA-DR, CD86 and CD83 were enhanced by oesophageal cancer; CD80, CD86 and CD83 were enhanced by rectal cancer, whereas CD54, HLA-DR, CD86, CD83 and PD-L1 were inhibited by colonic cancer. Notably, TCM from all GI cancer types inhibited TNF-α secretion. Additionally, TCM from irradiated biopsies inhibited DC markers. Profiling the TCM showed that IL-2 levels positively correlated with maturation marker CD54, while Ang-2 and bFGF levels negatively correlated with CD54. CONCLUSION: This study identifies that there are differences in DC maturational capacity induced by the TME of distinct gastrointestinal cancers. This could potentially have implications for anti-tumour immunity and response to radiotherapy.

Co-operative radical pelvic surgery: a role for the gynecologist in vaginal reconstruction using a uterine myoserosal flap in urological and anorectal cancer surgery.

This study describes a new technique for reconstructing the vagina and vestibule after radical extirpative surgery for urological and anorectal malignancy. The uterus is always excised when exenterative surgery is performed for gynecological cancer. The use of the uterus as a graft gives the gynecologic oncologist/reconstructive surgeon a role in the multidisciplinary team with urologists when the anterior vaginal wall and vestibule are excised and with the anorectal surgeons when the posterior vaginal wall and perineum are excised for nongynecological cancers. In some such cases, only the anterior or posterior wall of the vagina may be excised, leaving a healthy full-length, one-third, or half-circumference vaginal sleeve. A myoserosal flap is raised from the in situ uterus. The ectocervix is excised, and the adnexa are detached or excised. The uterus is opened to generate a hexagonal flap. The endometrium and endocervix are excised/ablated with electrocautery. The flap is advanced to the edge of the remaining anterior vestibule or reconstituted perineum. The serosal surface of the uterus forms the new wall of the vagina and undergoes metaplastic transformation to squamous epithelium within 3 months. The very satisfactory anatomical and functional outcome means that this technique merits further evaluation.

Introduction: Intradural Spinal Surgery video supplement.

This Neurosurgical Focus video supplement contains detailed narrated videos of a broad range of intradural pathology such as neoplasms, including intramedullary, extramedullary, and dumbbell tumors, vascular malformations, functional disorders, and rare conditions that are often overlooked or misdiagnosed such as arachnoid cysts, ventral spinal cord herniation, and dorsal arachnoid web. The intent of this supplement is to provide meaningful educational and instructional content at all levels of training and practice. As such, the selected video submissions each provide a comprehensive detailed narrative description and coordinated video that contains the entire spectrum of relevant information including imaging, operative setup and positioning, and exposure, as well as surgical strategies, techniques, and sequencing toward the safe and effective achievement of the operative objective. This level of detail often necessitated a more lengthy video duration than is typically presented in oral presentations or standard video clips from peer reviewed publications. Unfortunately, space limitations precluded the inclusion of several other excellent video submissions in this supplement. While most videos in this supplement reflect standard operative approaches and techniques there are also submissions that describe innovative exposures and techniques that have expanded surgical options such as ventral approaches, stereotactic guidance, and minimally invasive exposures. There is some redundancy in both the topics and techniques both to underscore fundamental surgical principles as well as to provide complementary perspective from different surgeons. It has been my privilege to serve as guest editor for this video supplement and I would like to extend my appreciation to Mark Bilsky, Bill Krauss, and Sander Connolly for reviewing the large number submitted videos. Most of all, I would like to thank the authors for their skill and effort in the preparation of the outstanding videos that constitute this video supplement.

Microsurgical resection of intramedullary spinal cord hemangioblastoma.

Spinal cord hemangioblastomas account for about 10% of spinal cord tumors. They usually arise from the dorsolateral pia mater and are characterized by their significant vascularity. The principles and techniques of safe resection are different than those employed for the more commonly occurring intramedullary glial tumors (e.g. ependymoma, astrocytoma) and consist of circumferential detachment of the tumor margin from the surrounding normal pia. This video demonstrates the microsurgical techniques of resection of a thoracic spinal cord hemangioblastoma. The video can be found here: http://youtu.be/yT5KLi4VyAo.

Resection of a cervical dumbbell schwannoma with stabilization through a single stage extended posterior approach.

Dumbbell tumors of the cervical spine can present considerable management challenges related to adequate exposure of both intraspinal and paraspinal tumor components, potential injury to the vertebral artery, and spinal stability. This video demonstrates the microsurgical removal of a large cervical dumbbell schwannoma with instrumented fusion via a single stage extended posterior approach. The video shows patient positioning, tumor exposure, and the sequence and techniques of tumor resection, vertebral artery identification and protection, and dural repair. The video can be found here: http://youtu.be/3lIVfKEcxss.

Release and repair of a ventral thoracic spinal cord herniation.

Ventral thoracic spinal cord herniation is a rare but increasingly recognized cause of progressive myelopathy. This video demonstrates the imaging characteristics and surgical techniques for release and reduction of the spinal cord herniation as well as primary repair and reinforcement of the ventral dural hernia defect through an extended posterior approach. An instrumented fusion was concomitantly performed. The video can be found here: http://youtu.be/6Pcokep6Tug.

Microsurgical resection of cauda equina schwannoma with nerve root preservation.

The occurrence of motor deficit following resection of an intradural spinal schwannoma is an uncommon but potentially serious complication. This video illustrates the technique of microsurgical resection of an L-4 sensory nerve root schwannoma with preservation of the corresponding functional L-4 motor nerve root. The video can be found here: http://youtu.be/HrZkGj1JKd4.

Microsurgical enbloc resection of myxopapillary cauda equina ependymoma.

Benign myxopapillary filum terminale ependymomas are often poorly encapsulated and in apposition the cerebrospinal fluid (CSF). These characteristics present the potential surgical risk of CSF dissemination or injury to the delicate cauda equina nerve roots. This video details the techniques of en bloc surgical resection of a filum terminale ependymoma. Treatment strategies and techniques are illustrated to reduce the risk of CSF dissemination and cauda equina injury. The video can be found here: http://youtu.be/LK8AYg-5T7o.

Dorsal arachnoid web.

Dorsal thoracic arachnoid web is a rare but often overlooked cause of progressive myelopathy. Syringomyelia, either above or below the compressive arachnoid band, may also be present. Dorsal arachnoid cyst and ventral spinal cord herniation may be mistaken for this condition. This video demonstrates the microsurgical identification and techniques of resection of a dorsal arachnoid band producing a progressive myelopathy in a 63-year-old man. The video can be found here: http://youtu.be/KDNTqiyW6yo.